It's more than what they know: spatial skill and conceptual understanding impact student interpretation skill

Sequence stratigraphy is a geologic field important to the petroleum industry, freshwater reservoir exploration, and paleontology.  Sequence stratigraphic interpretation skill is one of the top six skills looked for by industry employers. Yet, students struggle with the basic concepts of sequence stratigraphy, such as base level, relative sea level, global sea level, and accommodation. One reason for this is that these concepts are temporally and spatially complex, and spatial reasoning skills in particular often present a barrier to student success in the geosciences. Thus, it is crucial to understand the relationship between spatial skill and sequence stratigraphic interpretation skill and what instructional methods promote success in this area. This study seeks to 1) assess which spatial skills are important for sequence stratigraphic interpretation, 2) assess the impact of Wheeler diagram instruction on student sequence stratigraphic interpretation skill, and 3) contextualize students' errors on sequence stratigraphic interpretation tasks. This is a pre-/post- instruction study including participants from three U.S. institutions enrolled in upper-level sedimentology and stratigraphy courses or graduate-level sequence stratigraphy courses. Students completed a sequence stratigraphic interpretation assessment before and after Wheeler diagram instruction. After Wheeler diagram instruction, the students completed a knowledge survey and two spatial skill tests to measure disembedding and mental folding/unfolding. This study shows that: 1) students have difficulties identifying unconformities, changes in sea level, and full sequences, 2) mental folding and unfolding skill is key to student sequence stratigraphic interpretation, and 3) Wheeler diagram instruction helps initially lower-scoring students. These results inform on important skills and conceptual errors that should be targeted in future sequence stratigraphic training.